Effect of aging on human circulatory system in normotensive healthy subjects

Aging is associated with degenerative changes in cardiac and endothelial function (EF). This study was done to assess whether age-related changes take place on EF, carotid intima-media thickness (IMT), blood pressure (BP), and echocardiographic measurements. All volunteers were healthy normotensive healthy subjects. They were divided into three groups. Group 1, young adults: < 40 years old; Group 2, middle age: between 40 and 60 years old; Group 3, elderly: > 60 years old. High-frequency vascular ultrasound was used to assess the baseline brachial artery dimension and flow velocity after reactive hyperemia. The carotid IMT and echocardiographic measurements including Doppler variables were recorded in all subjects. Systolic BP, left ventricular mass, and left ventricular end-diastolic volume increased progressively with age (p < 0.001). Left ventricular ejection fraction decreased progressively with age (male, p = 0.034; female, p = 0.001); E/A ratio of the left ventricular flow spectrum declined with age (p < 0.001). The ultrasonic EF variables of flow increased during reactive hyperemia and IMT increased with age (p < 0.001). Our study demonstrates that BP, body weight, and ultrasonic variables changed significantly with age. The aging-associated changes provide insight into progression to atherosclerosis.